Aluminum-air batteries have the potential to produce power that operates mobile machines (e.g., automobiles). Aluminum-air batteries consume aluminum anodes as fuel and have an energy density that surpasses conventional battery technologies (e.g., lithium-ion batteries). When used to power a mobile machine, aluminum air batteries have a travel range comparable to vehicles powered by an internal combustion engine. However, aluminum-air batteries are not electrically rechargeable like many conventional batteries. Instead, aluminum-air batteries must be mechanically recharged by replacing the aluminum anode. The consumed aluminum anodes are converted into aluminum hydroxide by the electrochemical reaction taking place in the aluminum-air batteries. The aluminum hydroxide produced may be collected and recycled back into aluminum. The recycling process involves heating (i.e., calcining) the aluminum hydroxide to form aluminum oxide, mixing the aluminum oxide with various salts, and regenerating the aluminum oxide to aluminum by electrolysis.
Recycling the aluminum hydroxide can reduce the overall cost of aluminum-air batteries. However, the heating step (e.g., calcining) of the recycling process requires a significant amount of energy. In addition, even though aluminum-air batteries have an energy density greater than that of convention battery technology, limiting the footprint of the aluminum-air batteries and corresponding system is a challenge for mobile machine applications where space is limited.
One article analyzing the use of aluminum-air batteries in electric vehicles was written by Shaohua Yang & Harold Knickle, and is titled Design and Analysis of Aluminum/Air Battery System for Electric Vehicles. The article was published in 2002 by the Journal of Power Sources, at pages 162-173. The article discusses the fuel cost and efficiency of aluminum-air batteries, as well as the recycling process. The article compares aluminum-air batteries to lead/acid batteries and nickel-metal hybride battery. Although the article breaks down the cost, efficiency, and recycling process for aluminum-air batteries, it does not put forth solutions for reducing the high energy needs for aluminum hydroxide recycling or reducing the footprint of the aluminum-air battery system.
The aluminum-air battery power system of the present disclosure is directed to overcoming one or more of the problems set forth above.